Has there been any indication that Skype partnered with another carrier or smartphone platform for a period of exclusivity on features of availability. Trying to remember if Android phones are going to be billed for calls like iPhones will be after the "intro" period.

What of other VoIP clients that exist for the iPhone, such as Fring? Should I be able to expect those to support the multitasking feature of ios4?

Has there been any indication that Skype partnered with another carrier or smartphone platform for a period of exclusivity on features of availability.

Nope. There's no benefit to Skype doing that (esp. since there really isn't much in way of 'features' to exclusiveise.

Trying to remember if Android phones are going to be billed for calls like iPhones will be after the "intro" period.

That's up to the network, not Skype. From what I gathered, ATT insisted that Skype not be allowed to run on its network without getting a nice fat chunk of change in return, which Skype is passing onto its users (no other way to look at that, esp. since wi-fi calling would still be free).

iOS 4 is due to launch on iTunes later today, and it's considered unusual that the Skype update is not already available. An early version was demonstrated as far back as March, showing multitasking abilities that should make the VoIP app more useful on Apple handhelds

As any programmer will tell you, it's easy to get to the demonstration stage. Getting all the kinks worked out is another deal altogether.

I beleve The right-side pic is holding it right.
well, glad to hear that skype for 3G is free.
"Well, it's about time. Touted back in March as one of the pillar apps to benefit from the new multitasking API, Skype has finally been updated to iOS 4 compatibility." and good update!
for iOS4, 'iOS4: Everything You Need to Know' and iOS 4 Upgrade Guide: Install iOS 4 on Your iPhone -> A guide helps you upgrade your iPhone or iPod Touch to Apple's new iOS 4: iFunia iPhone Column